1. Field of the Invention
This invention relates to vehicle suspensions and, in particular, to a vehicle suspension in which a spring is mounted remote from the vehicle axle.
2. Disclosure of Related Art
In most conventional vehicle suspensions, one or more springs are disposed between the vehicle axle and the vehicle frame to dampen forces exerted on the vehicle as the wheels of the vehicle follow the road contour. Typically, these springs are mounted in a spring seat formed directly in the axle housing or coupled thereto. The relatively large size of conventional mechanical and air springs, however, renders it difficult to provide adequate space for the springs proximate the axle and increases the difficulty of suspension design. Further, the springs must be disposed relatively far inboard on the axle. As a result, vehicles often lack sufficient roll stiffness.
There is thus a need for a vehicle suspension that will minimize or eliminate one or more of the above-mentioned deficiencies.
The present invention provides a vehicle suspension that allows a spring to be mounted remote from the vehicle axle.
A vehicle suspension in accordance with the present invention includes a first assembly having a first member and a second member arranged in telescoping relation with the first member for relative movement along a first axis. The first member may be coupled to the vehicle axle while the second member may be coupled to the vehicle frame. The first assembly defines first, second, and third fluid chambers. The first assembly further includes a damping control device that controls fluid flow between the first and second fluid chambers of the first assembly. The inventive suspension also includes a second assembly having a first member and a second member arranged in telescoping relation with the first member for relative movement along a second axis. The second assembly defines first and second fluid chambers and includes a damping control device that controls fluid flow between the first and second fluid chambers. The first fluid chamber of the second assembly is of constant size and is in fluid communication with the third fluid chamber of the first assembly. The second fluid chamber of the second assembly is of variable size. The suspension finally includes a spring disposed against a frame of the vehicle and controlled responsive to movement of the second member of the second assembly.
A vehicle suspension in accordance with the present invention represents a significant improvement as compared to conventional vehicle suspensions. The inventive suspension enables the spring or springs of the suspension to be mounted remotely from the vehicle axle. As a result, less clearance is required in the area around the axle to accommodate the spring(s) thereby enabling easier design and packaging of suspension systems. The inventive suspension also provides greater roll stiffness than conventional systems by moving the reaction points of the spring further outboard. In particular, the first assembly may be mounted between the axle and vehicle frame outboard of the longitudinal frame rails of the vehicle-unlike most conventional mechanical and air springs-because the first assembly can operate a higher working pressures and, therefore, has a smaller diameter than conventional mechanical and air springs. The inventive suspension is also advantageous because compression and rebound damping forces are contained within the first and second assemblies and the suspension separates the rebound damping required for the spring from that required for the unsprung mass of the vehicle.
These and other features and objects of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawings illustrating features of this invention by way of example.